freetype2/src/smooth/ftsmooth.c

#include <freetype/internal/ftobjs.h>
#include <freetype/ftoutln.h>
#include <ftsmooth.h>
#include <ftgrays.h>

 /* initialise renderer - init its raster */
  static FT_Error ft_smooth_init( FT_Renderer  render )
  {
    FT_Library  library = FT_MODULE_LIBRARY(render);
    
    render->clazz->raster_class->raster_reset( render->raster,
        library->raster_pool, library->raster_pool_size );

    return 0;
  }
  


 /* sets render-specific mode */
  static  FT_Error  ft_smooth_set_mode( FT_Renderer  render,
                                        FT_ULong     mode_tag,
                                        FT_Pointer   data )
  {
    /* we simply pass it to the raster */
    return render->clazz->raster_class->raster_set_mode(
                    render->raster, mode_tag, data );
  }                                          

 /* transform a given glyph image */
  static  FT_Error  ft_smooth_transform( FT_Renderer   render,
                                         FT_GlyphSlot  slot,
                                         FT_Matrix*    matrix,
                                         FT_Vector*    delta )
  {
    FT_Error error = FT_Err_Ok;
    
    if (slot->format != render->glyph_format)
    {
      error = FT_Err_Invalid_Argument;
      goto Exit;
    }
    
    if (matrix)
      FT_Outline_Transform( &slot->outline, matrix );
      
    if (delta)
      FT_Outline_Translate( &slot->outline, delta->x, delta->y );
    
  Exit:
    return error;
  }

 /* return the glyph's control box */
  static  void  ft_smooth_get_cbox( FT_Renderer   render,
                                    FT_GlyphSlot  slot,
                                    FT_BBox      *cbox )
  {
    MEM_Set( cbox, 0, sizeof(*cbox) );

    if (slot->format == render->glyph_format)
      FT_Outline_Get_CBox( &slot->outline, cbox );
  }                                      
  

 /* convert a slot's glyph image into a bitmap */
  static  FT_Error  ft_smooth_render( FT_Renderer  render,
                                      FT_GlyphSlot slot,
                                      FT_UInt      mode,
                                      FT_Vector*   origin )
  {
    FT_Error     error;
    FT_Outline*  outline;
    FT_BBox      cbox;
    FT_UInt      width, height, pitch;
    FT_Bitmap*   bitmap;
    FT_Memory    memory;
    
    FT_Raster_Params  params;
    
    /* check glyph image format */
    if (slot->format != render->glyph_format)
    {
      error = FT_Err_Invalid_Argument;
      goto Exit;
    }
    
    /* check mode */
    if ( mode != ft_render_mode_normal )
      return FT_Err_Cannot_Render_Glyph;
      
    outline = &slot->outline;
    
    /* translate the outline to the new origin if needed */
    if (origin)
      FT_Outline_Translate( outline, origin->x, origin->y );
    
    /* compute the control box, and grid fit it */
    FT_Outline_Get_CBox( outline, &cbox );
    
    cbox.xMin &= -64;
    cbox.yMin &= -64;
    cbox.xMax  = (cbox.xMax+63) & -64;
    cbox.yMax  = (cbox.yMax+63) & -64;

    width  = (cbox.xMax - cbox.xMin) >> 6;
    height = (cbox.yMax - cbox.yMin) >> 6;
    bitmap = &slot->bitmap;
    memory = render->root.memory;
    
    /* release old bitmap buffer */
    if ((slot->flags & ft_glyph_own_bitmap))
    {
      FREE(bitmap->buffer);
      slot->flags &= ~ft_glyph_own_bitmap;
    }
      
    /* allocate new one, depends on pixel format */
    pitch = width;
    bitmap->pixel_mode = ft_pixel_mode_grays;
    bitmap->num_grays  = 256;
    bitmap->width      = width;
    bitmap->rows       = height;
    bitmap->pitch      = pitch;
    
    if (ALLOC( bitmap->buffer, (FT_ULong)pitch * height ))
      goto Exit;

    slot->flags |= ft_glyph_own_bitmap;
    
    /* translate outline to render it into the bitmap */
    FT_Outline_Translate( outline, -cbox.xMin, -cbox.yMin );

    /* set up parameters */
    params.target = bitmap;
    params.source = outline;
    params.flags  = ft_raster_flag_aa;

    /* render outline into the bitmap */
    error = render->raster_render( render->raster, &params );
    if (error) goto Exit;
    
    slot->format      = ft_glyph_format_bitmap;
    slot->bitmap_left = cbox.xMin >> 6;
    slot->bitmap_top  = cbox.yMax >> 6;

  Exit:
    return error;
  }


  const FT_Renderer_Class  ft_smooth_renderer_class =
  {
    {
      ft_module_renderer,
      sizeof( FT_RendererRec ),
      
      "smooth",
      0x10000,
      0x20000,
      
      0,    /* module specific interface */
      
      (FT_Module_Constructor)  ft_smooth_init,
      (FT_Module_Destructor)   0,
      (FT_Module_Requester)    0
    },

    ft_glyph_format_outline,
    
    (FTRenderer_render)       ft_smooth_render,
    (FTRenderer_transform)    ft_smooth_transform,
    (FTRenderer_getCBox)      ft_smooth_get_cbox,
    (FTRenderer_setMode)      ft_smooth_set_mode,
    
    (FT_Raster_Funcs*)        &ft_grays_raster
  };